In modern flight decks, the primary flight information display (PFD) and the navigation display (ND) are the key displays available for providing situational awareness to the pilot. Although the primary flight information display provides aircraft attitude and performance information through the attitude direction indicator (ADI), airspeed tape, heading and track indicator, and vertical speed indicator (VSI), the performance information is not shown in relation to the aircraft""s surroundings. The navigation display provides fairly complete horizontal situational awareness with a top down (map) view of the aircraft and its surroundings. The navigation display tries to address vertical situational awareness through a vertical path deviation indicator, waypoint altitude constraint information, a range to altitude arc, and a selectable terrain picture from a Terrain Awareness and Warning Systems (TAWS). TAWS provides a contour map of surrounding terrain. Due to the display shading limitations and the nature of a top down view display, the contour map can only provide a general awareness of the surrounding terrain height. Also, to avoid pilot complacency and possible false alarms on takeoff and landing, some systems may have a xe2x80x9cblackoutxe2x80x9d elevation below which the display provides no terrain information in normal conditions. Even with these vertical situational awareness features on the navigation display, the information still requires some interpretation, and approach and landing accidents continue to occur. This leaves the pilot with TAWS to provide both horizontal and vertical situational awareness of terrain. The pilot may not be able to perform an optimal vertical maneuver if the pilot is not aware of the height of the surrounding terrain. For flight deck displays that show the terrain directly in front of the aircraft, the input for this type of device may be a database of topography information that generates a display based on position information from the aircraft""s navigational equipment. However, the display changes with slight adjustments to the direction of the aircraft, making it appear xe2x80x9cnoisyxe2x80x9d. Also, navigational instruments for determining the exact position of an aircraft usually have some degree of error. For example, if the aircraft""s automated navigational equipment is only accurate to within 10 nautical miles of the exact location of the aircraft, and the topography display only shows a xe2x80x9clinexe2x80x9d of topography directly in front of where the aircraft instruments indicate the aircraft is located, the topography display will be not be accurate as to the topography directly in front of the aircraft if the aircraft""s exact position is actually 9.5 nautical miles from the location indicated by the navigation equipment. A presentation of terrain and waypoints along the current track of the aircraft provides some awareness, but during turns the pilot will not see terrain in the projected path of the turn.
To assist pilots with final approach and landing, a localizer and a glideslope indicator may be provided on the electronic attitude director indicator to give the pilot information as to how much the aircraft is deviating from the ideal landing approach angle, as defined by a radio signal from the runway. When the aircraft is not on this ideal path, the flight deck instruments do not indicate the degree of correction required to return the aircraft to the correct descent path. If the pilot under- or overcorrects the descent angle and cannot position the aircraft onto a suitable landing approach path in a short period of time, the pilot may have to make a decision to abort the landing, circle, and begin another landing approach. A system that gives the pilot better information about the current relationship between the aircraft and the ideal descent and landing approach path will aid the pilot.
At various times during ascent and descent of an aircraft, it may be necessary for the aircraft to reach a target speed by the time the aircraft reaches a particular geographic point. The airspeed tape on the primary flight information display indicates current and selected airspeeds, but the pilot has to judge how long it will take to achieve the selected airspeed. The pilot then needs to calculate how far the aircraft will travel before the target speed is achieved. These calculations and estimations may not be very precise and may distract the pilot from performing other duties connected with flying the aircraft and maintaining an accurate mental picture of the situation.
For many of the flight information displays in the cockpit, the reference mark by which the instrument is read is either fixed with a moving scale to indicate the value of parameter (for example, an altimeter tape) or the reference mark moves with respect to a fixed scale (for example, a vertical speed indicator). If the reference aircraft symbol on a vertical profile display (VPD) is fixed near the bottom of the display and the aircraft is in a descent, the resolution of the display for that range of altitudes will be insufficient to provide the pilot with any increased awareness of the terrain the aircraft is approaching. Similarly if the aircraft symbol is fixed at the top of the display and the aircraft is climbing, resolution will be insufficient to increase the pilot""s awareness of the airplane""s relationship with the terrain ahead.
One known type of vertical display provides a terrain picture for the navigation displays, EHSIs, and standalone weather radar display units. Another known vertical profile display depicts the flight plan in an along flight plan presentation. The waypoints are positioned relative to each other and not on an absolute scale (For example, if waypoint A is at FL390 and waypoint B has an altitude constraint of FL410, then waypoint A will be at a position on the display lower than waypoint B, but otherwise the vertical position of the points will not correlate to any absolute scale). A display that provides better vertical flight situation awareness to the pilot would be desirable.
In one aspect, this invention is a flight information display for the flight deck of an aircraft showing a pictorial side view of the flight path or the area directly in front of the aircraft area having a selected distance of at least 0.5 nautical miles, comprising (a) a pictorial representation to scale of the profile of the highest elevations of a swath of terrain along said path or area, (b) an icon positioned on the left or right side of the display representing the aircraft, the altitude of which is to scale with the height of the terrain, and (c) an altitude reference scale;
wherein the width of the swath is at least 0.1 nautical miles and no greater than the distance of the minimum accuracy of the means for determining the aircraft""s location.
In another aspect, this invention is a flight information display for the flight deck of an aircraft showing a side view of the landing approach for the aircraft on a runway, comprising (a) a pictorial representation to scale of the profile of the current projected path of the descent of the aircraft, (b) a pictorial representation to the same scale of the profile of the vertical glide path of the approach, (c) an icon positioned on the left or right side of the display representing the aircraft; the altitude of which is depicted to the same scale, and (d) an altitude reference scale.
In a third aspect, this invention is a flight information display for the flight deck of an aircraft comprising (a) a reference point or icon representing the current location of the aircraft, (b) a pictorial representation of at least 0.5 nm of the profile of the projected flight path of the aircraft, (c) a an icon showing the location at which the aircraft will reach a target speed based on its current speed and acceleration. This display provides an indication of where in the vertical plane and along the flight path the target speed will be achieved.
In a fourth aspect, this invention is a flight information display for the flight deck of an aircraft, which comprises (a) an icon having a fixed position on the right or left side of the display representing the aircraft; (b) a vertical altitude scale which changes as the altitude of the aircraft changes so that the altitude number horizontally aligned with the aircraft icon is the current altitude of the aircraft and the aircraft icon is located vertically along the altitude reference scale while always being in view, and (c) a pictorial representation of a lateral view of any terrain directly in front of the aircraft.
The above-described display of the invention provides flight information to assist the pilot in avoiding terrain collisions or making more efficient and safe landing approaches. The displays provide this information in a format that is relatively intuitive for the pilot to understand without substantial analysis, interpretation, false alarms, or unnecessary distraction from other duties, and
conforms to standard graphical depictions used on approach charts and other places in the flight deck, thereby allowing the pilot to make any necessary adjustments to the speed and direction of the aircraft relatively quickly and precisely.